Apparatus for the production of dot-composed negatives



Dec. 5, 1950 L. M. VAN DER ROHE ET AL APPARATUS FOR THE PRODUCTION OFDOT-COMPOSED NEGATIVES 5 Sheets-Sheet 1 Filed June 26, 1946 mWATf/Fffff/SWANS Z ATTORNEY Illlllllllfllll lllllilllflll I Dec. 5, 1950L. M. VAN DER ROHE ET AL 2,532,535

APPARATUS FOR THE PRODUCTION OF DOT-COMPOSED NEGATIVES 5 Sheets-Sheet 2Filed June 26, 1946 WIIIXIIIIA Dec. 5, 1950 L. M. VAN DER ROHE ET AL 5 5APPARATUS FOR THE PRODUCTION OF DOT-COMPOSED NEGATIVES Filed June 26,1946 3 Sheets-Sheet 5 Patented Dec. 5, 1950 APPARATUS FOR THE PRODUCTIONOF DOT-COMPOSED NEGATIVES Ludwig Mies van der Rohe and Walter Peterhans,

Chicago, 111.

Application June 26, 1946, Serial No. 679,308

4 Claims. (01. 88-24) This is a continuation-in-part of patentapplication Ser. #430,974, filed February 14, 1942, now abandoned, thelatter being a continuationin-part of patent application Ser. #252,654,filed January 24, 1939, which has matured into Patent #2282337 on May12, 1942.

Our invention relates to photography, and more particularly to anapparatus for the production of dot-composed or screened negatives.

The conventional apparatus for the production of dot-composed negativesrequire the use of a half-tone screen of substantially the same size asthe negative. Half-tone screens are comparatively expensive, and, if ahalf-tone screen exceeds a certain size, the costs of manufacture ofsuch large half-tone screens becomes so high, that they are burdensomefor the trade. Therefore, hitherto placards or other large sheetsbearing reproductions of images have been usually manufactured in such amanner, that a plurality of small dot-composed negatives are produced bythe use of small half-tone screens and an equal number of electrotypesare prepared from said negatives. Each of said electrotypes is used forthe reproduction of images forming a portion of the entire image onsmall sheets, and several individual small sheets are then pasted on aboard to form in combination a placard showing the entire image.

An object of our invention is to provide an apparatus, by means of whicha small half-tone screen may be used for the production of acontinuously coherent dot-composed reproduction of a positive on anegative of any larger size than that of the half-tone screen, so thatthe available half-tone screens of small size only may be used for theproduction of large sheets bearing reproductions, such as placards,wallpaper, etc.

With the above and other objects of the invention in view, the inventionconsists in the novel construction, arrangement and combination ofvarious devices, elements and parts, as set forth in the claims hereof,certain embodiments of the same being described in the speciiication andbeing illustrated in the accompanying drawings forming part of thisspecification, wherein:

Fig. 1 is a diagrammatic top plan view, partly in section, of anapparatus according to the invention,

Fig. 2 is a view of a portion of a half-tone screen and a mask in anenlarged scale,

Fig. 3 is a diagrammatic view of a negative and a half-tone screen, thelatter being shown in its starting position and in its end position,

Fig. 4 is a diagrammatic top plan view, partly in section, of anotherembodiment of an apparatus according to the invention, wherein thehalf-tone screen is moved step by step,

Fig. 5 is an elevational view of the half-tone screen and the mask ofthe apparatus shown in Fig. 4, in an enlarged scale,

Fig. 6 is a sectional view taken on line 66 of Fig. 5,

Fig. '7 is a fragmentary elevational view of a half-tone screen and amask equipped with automatic means for causing a predeterminedstepby-step movement of the half-tone screen,

Fig. 8 is an elevational view, partly in section, of a latch mechanismshown in Fig. '7, and

Fig. 9 is a diagrammatic perspective view of the shutter, the objective,the half-tone screen, the mask, and driving means of another embodimentof an apparatus according to the invention, wherein the half-tone screenis continuously moved.

Referring now to Fig. 1, It! generall indicates a camera, which ismounted on a base I2 in any suitable manner. A mounting l4 rigidlysecured to the base i2 by suitable means is arranged opposite theobjective 23 of the camera It having a lens 25. A positive I8 may beattached to said mounting M in any suitable manner. A negative 23 in theshape of a film or a plate may be attached to a stationary holder 32arranged inside the camera Hi. Thus, the positive 3 and the negative 28are held in a fixed position with respect to each other and to theoptical axis of the objective 23. An opaque endless belt or mask 40surrounding the negative 23 is guided by rollers c2 rotatably mounted ina frame 4 Said mask 46 is provided with a window 54 receiving ahalf-tone screen 30 or" a size smaller than the size of the negative 23.The half-tone screen has a plurality of opaque dots 53 and transparentdots 59 as best shown in Fig. 2 in an exaggerated scale. According toFig. 1, one of the rollers 42 is provided with a handle 56, so that themask 48 and the half-tone screen 3c may be moved in close proximity tothe negative 28 so as to place consecutive portions of the negativebehind the half-tone screen. The portions of the negative not placedbehind the half -tone screen are shielded by the mask 4%. A shuttergenerally indicated by 6%, which may be actuated by a suitable wirerelease or trigger (not shown), may be used for exposing suchconsecutive portions of the negative 28 to corresponding consecutiveportions of the positive I8. According to Fig. 2, the trailing edge GIand the leading edge 62 of the window 5:3 of the mask as are parallel toeach other. The distance cl between said edges BI and 62 is in such apredetermined relationship to the pattern of dots 53, 59 of thehalf-tone screen 3% arranged in the window 54, that the pattern of dotsof the half-tone screen appearing in the window adjacent the trailingedge BI represents a continuation of the pattern of dots of thehalf-tone screen appearing in the window adjacent the leading edge t2.

When the apparatus shown in Fig. l is used for the production of dotcomposed: negatives by step-by-step movements of the half-tone screen 30and the mask lit, at first the handle 56 is rotated so as to bring thehalf-tone screen 33 into a position in front of the portion a of thenegative 28. When the half-tone screen 3% is at a standstill in saidposition in front of the portion a of the negative, a first exposure ismade by an actuation of the shutter 68, so that the portion a of thepositive I8 is reproduced through the half tone screen on said portion aof the negative 28. After said first exposure has been made, the handle55 is turned so as to displace the halftone screen SE! is the directionA through a distance equal to its width 01' appearing in the window 5;of the mask to, whereby the half-tone screen is brought into a positionin front of the consecutive portion 2) of the negative 23. Now, whenthehalf-tone screen 39 is at a standstill in said. position in front of theportion b of the negative, a second exposure is made by means of theshutter 5%, so that the consecutive portion 1) of the positive I8 isreproduced through the half-tone screen on said portion 12 of thenegative. As will be readily understood from Fig. 2, said displacementof the half-tone screen 33 in the direction A through a distance equalto its width (2 brings the trailing edge 6| into a position previouslyoccupied by the leading edge 82. Therefore, the pattern of dots producedduring said second exposure by means of the half-tone screen 39 on theportion 2) of the negative 28. is in continuity with the pattern of dotsproduced during the first exposure by means of the halftone screen onthe portion a of the negative. After said second exposure, the half-tonescreen 38 is again displaced in the directionA through a distance equalto its. width d, until it reaches a position in front of the consecutiveportion of the negative 28. Thereupon, when the halftone screen is at astandstill, a third exposure is made for reproducing the consecutiveportion 0 of the positive I8 through the half-tone screen on the portion0 of the negative. Thus, a continuously coherent dot-composedreproduction of. the positive composed of a plurality of separatereproductions of consecutive portions a, b, c of the positive I8 isprepared. The dot composed negative thus obtained may be removed fromvthe camera and may be used for the production of an electrotypeaccording to any conventional process. Fig. 1 illustrates the threesteps a, b and c for the production of a dot composed negative; it isunderstood, however, that a larger number of steps is used, when thewidth of the half-tone screen is smaller inproportion to the length ofthe negative.

According to the embodiment of an apparatus shown in Figs. 4-6, againthe camera I I0 is mounted on a base H2, and the positive H8 attached tothe stationary mounting He and the negative 523 carried by the holderI32 are held in a, fixed position relative to each other and to theoptical axis of the objective I2 5. The halftone screen I36 is mountedin a carriage I53 having rollers I6 for engagementwith stationary tracksI85, I56 arranged in the camera H8. The

ends of a flexible opaque mask I 58 laid around rollers M2 journalled instationary parts of the camera iii are secured to the carriage I63 byscrews Iii'i in such a manner, that the trailing edge It! and theleading edge I52 are in the same relationship to the pattern of dots ofthe half-tone screen I38 as described above in connection with thetrailing edge iii and leading edge $2 of the window 54 of the mask 40shown in Fig. 2. The half-tone screen ISiB arranged in the carriage its.connected with the mask I i!) may be moved along the tracks :55, 258 byrotating a handle I53 arranged on one of the rollers I52. A series ofequally spaced indicating marks M1, M2, M3 are arranged on the trackI65. Said indicating marks M1, M2, M's are at a distance e from eachother equal to the width at of the halftone screen I30 appearing in thewindow I54 of the mask MS. Furthermore an indicating arrow or indicatingmeans M is arranged on the carriage I63 for cooperation with saidindicating marks M1, M2, M3. The indicating arrow M and the indicatingmarks M1, M2, M3 are visible through a window (not shown) of the camera.

When the apparatus shown in Figs. 4-6 is used, at first the half-tonescreen I39 is displaced along the tracks 965, I55, until the indicatingarrow M is in register with the first indicating mark M1 of the seriesof indicating marks M1, M2, M3, so that the half-tone screen I3!) is infront of the portion a of the negative I23 as shown in Figs. 4 and 5.Now, when the half-tone screen I35! is at a standstill, a first exposureis made by an actuation of the shutter I58 for the reproduction of aportion of the positive on said portion a of the negative I28. Aftersaid first exposure, the half-tone screen I33 is moved by a rotation ofthe handle I55, until the indicating arrow M is in register with thesecond indicating mark M2, so that the half-tone screen is displaced onestep through a distance equal to its width d into a new position infront of the consecutive portion b of the negative. When the half-tonescreen is at a standstill in said new position, a second exposure ismade. Thereafter, the half-tone screen is moved another step, until theindicating arrow M appears opposite the third indicating mark Me, sothat the half-tone screen is in front of the consecutive portion 0 ofthe negative. Now, the half tone screen being at a standstill, a thirdexposure may be made. Thus, the indicating marks M1, M2, M3 incooperation with the indicating arrow M represent spacing means servingas controlling means for the determination of the proper stepby-stepmovement of the half-tone screen, so that the exposures may be carriedout at the proper moments when the half-tone screen is. moved into aposition wherein an exposure produces a pattern of dots on the negativein continuity with the pattern of dots produced by a preceding exposure.

Fig. 7 illustrates a mask and half-tone screen arrangement withmechanical controlling means for the step-by-step movement of thehalf-tone screen, which may be substituted for the mask and half-tonescreen arrangement of the apparatus shown in Figs. 4-6. According toFig. "I, t -e carriage I63 holding the half-tone screen E3!) is slidablyengaged with the stationary tracks 55, I .arranged inthe camera Hi); Theends of the flexible mask I40 are secured to the carriage I63 in thesame manner as described above in connection with Fig. 5, so that theedges I'6I and I62 are in the proper relationship to the pattern of dotsof the half-tone screen I30. A series of latch-mechanisms generallyindicated by L1, L2 to be described hereinafter is attached to the trackI65. The various latch-mechanisms are spaced from each other at equaldistances, so that the distance between the effective edge of thestopping means I68 of adjacent latchmechanisms equals the width at ofthe half-tone screen I30 appearing in the window I54 of the mask I40. Anabutting member I04 is attached to the carriage I63 for cooperation withthe effective edge of the various stopping means I68. As best shown inFig. 8, each stopping means I68 comprises a member I 69 swingablymounted on a pin I10 arranged on the stationary track I65. An adjustingscrew I1I having the effective edge I12 for cooperation with theabutting member I84 is screwed into threaded bores of the swingablemember I69. A locking element I13 screwed on the threaded shaft of theadjusting screw Iii may be used to hold same in a predetermined adjustedposition. A latch I14 swingably mounted at I15 on a plate I16 secured tothe track I65 is arranged for cooperation with the edge I11 of theswingable member I59. A spring I18 ar ranged between a flange I19 0f theplate I16 and the latch I14 tends to urge normally the latch against astop I00, so that the latch is in engagement with the swingable memberI69 and holds the effective edge I12 of the adjusting screw I1I in thepath of the abutting member I84. Each latch-mechanism L1, L2, isprovided with an electromagnet I8I arranged opposite the latch 214. Eachelectrofnagnet I8I may be individually energized for lifting the latchI14 into the position I14 shown in dash and dot lines in Fig. 8. Thecarriage IE3 is under the action of a. load I82 connected with thecarriage by a cord I83 laid around a roller I85 as shown in Fig. 7. Saidload I82 urges the abutting member I34 of the carriage I'63 against theeffective edge I12 of one of the stopping means I68 normally held in thepath of the abutting member by the spring loaded latch I14.

When an apparatus equipped with the mechanism shown in Figs. '1 and 8 isused, at first the movable half-tone screen is brought into the positionshown in Fig. '1, wherein the abutting member I84 abuts against theeffective edge of the stopping means I68 of the first latch mechanismL1, so that the half-tone screen I is at a standstill in front of thefirst portion of the negative. Thereupon, the first exposure is made.After said first exposure, the electromagnet I8I of the firstlatch-mechanism is energized, whereby the latch I14 thereof is liftedinto the position I14 shown in dash and dot lines in Fig. 8, so that theabutting member I84 being under the action of the load I82 may swing thestopping means I68 about the pivot I10 out of its path into the positionIE8 shown in dash and dot lines in Fig. 8, whereby the half-tone screenI30 is automatically displaced one step through a distance f equal toits width d, until the abutting member I84 hits against the effectiveedge of the next stopping means I68 held in its path by the springloaded latch of the next latch mechanism L2. After the passing of theabutting member I84 under the stopping means I68 of the first latchmechanism L1, the stopping means of the latter returns by its own weightinto its normal position shown in full lines in Fig. 8, whereupon theelectromagnet I8I of the first latch-mechanism may be deenergized forcausing a locking of the stopping means by the spring loaded latch I14.Now, when the half-tone screen is held by the stopping means I68 of thelatch mechanism L2 at a standstill in front of a second portion of thenegative being consecutive to the first portion of the negative, asecond exposure may be made. After said second exposure, theelectromagnet I8I of the second latch-mechanism is energized, whereby afurther step-movement of the half-tone screen is obtained in the samemanner as described above. The step by step movements of the half-tonescreen and the exposures between the steps when the half-tone screen isheld in its position by a stopping means of a latch-mechanism may berepeated as often as necessary in dependence on the number oflatch-mechanisms arranged in the apparatus.

According to Fig. 7, the various latch mechanisms L1, L2, the number ofwhich corresponds to the number of step-displacements to be carried outby the half-tone screen, are arranged only on the upper track I65. Ifdesired, however, an equal number of latch mechanisms may also bearranged on the lower track I66 for cooperation with a second abuttingmember secured to the carriage I63 holding the half-tone screen I30.

For the sake of simplifying the explanation of the apparatus with acontrolled step-by-step movement of the half-tone screen, the assumptionhas been made above, that the distance c between the indicating marksM1, M2, M or the distance between the efiective edges I12 of the variousstopping means I68 of the various latchmechanisms L1, L2 is equal to thewidth d of the half-tone screen appearing in the window I54 of the maskI49. This assumption is correct, if the half-tone screen is in contactwith the surface of the negative. In practice, however, there may be aslight space I99 (see Fig. 6) of a thickness of a few millimetersbetween the half-tone screen I30 and the negative I28. If this is thecase, the distance between adjacent indicating marks or the distancebetween the effective edges of adjacent stopping means should beslightly larger (about to 2 millimeters) than the width at of thehalftone screen. The exact length of the distance may be readily foundby calculations or a few experiments. The adjustable screws I1I of theembodiment shown in Figs. 7 and 8 permit an easy adjustment of the exactdistance between the effective edges I12 of adjacent stopping means I68.

During above described methods for the reproduction of dot composednegatives the half-tone screen is moved step by step. However, themethod for the reproduction of dot composed negatives with the positiveand negative held in a fixed position relative to each other and to theoptical axis of the objective may also be carried out with a continuousmovement of the halftone screen.

Fig. 9 illustrates diagrammatically the mechanism for a continuous driveof the half-tone screen and for making automatically exposures in timedrelationship to the movement of the half-tone screen. It is understood,that the tracks 265, 266, the slidable carriage 263 holding the screen230, and the flexible mask 245 laid around the rollers 242 take theplace of the corresponding elements of the apparatus shown in Figs. 4and 5, when an apparatus according to the invention is designed for acontinuous movement of the half-tone screen. According to Fig.

9:22; threaded spindle 236 is'rotata-bly but axially immovably arrangedin, brackets 2E1 mounted on the stationary track 266. An element 238attached to; the carriage 263 has athreaded bore in engagement with thethreaded portion of the spindle 28-6. A sprocket wheel 289 is keyed toone end. of said spindle 286. 7

Another sprocket wheel 296 of exactly the same size and shape as thesprocket wheel 28% is keyed; to ashaft 25I journalled in suitablebearingslnot shown) of the apparatus. Furthermore, a disk-like shutter.286 is keyed to said shaft 29 I, so that said shutter 26% may be rotatedby a rotation of. the sprocket wheel 298. The shutter 260 arranged infront of the objective 223 has a series of equally spaced openings 292each having a width 9. being a predetermined fraction of the distance71, between adjacent openings.

A further sprocket wheel 293 is keyed tothe driving shaft 295 of anelectromotorZtii. Furthermore, an idling wheel 29a; is loosely butaxially immovably arranged on said shaft 294-. A chain 291 is trainedaround the sprocket wheels 2.89, 2.98, 293 and the idling wheel 28B.will be readily understood. a rotation of the driving. shaft 294 of theelectromotor 295 causes a rotation of the threaded spindle 28% and thedisklike shutter 266 at the same speed, as the sprocket wheels 289 and29s are of ,the same size. Furthermore, as the half-tone screen 232' ismoved along the negative I28 carried by the holder 32 by a rotation of.the threaded spindle 255 and as al ght flash is produced every time anopening 2-92 of the rotatable shutter Ziiil passes the objective 223,light flashes will be produced in a predetermined relationship to themovement of the half-tone screen 239.

As an example for the various relationships between the mechanismsv ofthe apparatus for the production of. a continuously coherent dotcomposedreproduction of a positive on negative the following dates may be given:

Assume that the negative 828 has a length i of 1- meter (see Fig. '3)and that 400i) dots 2&8 are to be produced at extremely small equaldistances in a row on said negative I28 during a continuous movement ofthe half-tone screen 239 at a constant speed in the direction of thearrow B from the starting position shown in full lines into the endposition 238 shown in dash and dot lines. Furthermore, suppose, thehalf-tone screen 2 38 has a width 02 of meter. Under these circumstancesthe half-tone screen 239 is to be moved into the position 230 through adistance z'+d=l /1o meters, and 440!) instantaneous exposures are to bemade at regular intervals. As mentioned above, 400G dots are topsreproduced on the length i=1 meter of the negative HS; consequently,each dot has a width of /4 meter or A; millimeter, and likewisathewidth5 (Fig. 2)- of a transparent dot of the halt-tone screen 239= Amillimeter.

Furthermore, assume that the spindle 235 (Fig. 9) has 10 threadsercentimeter; that the shutter 260 has four open gs each having a widthg= of the distance it between adjacent openings, and that the shuttermake 1' revolution per second. Then the half-tone screen FEM-will: move1 millimeter durin se ond or mi limeter during' ,4, of a secofurthermore, a light of 4 of a second will: pass through the halt-tonescreen every 4 of, second.

As mentioned; above, each transparent dot. of the half-tone screen has awidth of A; of a millimeter and the, half-tone screen ismoved /4 of amillimeter during ofa second. Therefore, the transparent dots of thehalf-tone screen are moved through a distance equal to their Widthduring 4 of a, second. Moreover, as mentioned above, a light flash of Ofa second passes through the half-tone screen every A; of a second. Inother words, the. time or" the instantaneous exposure is ,4, of second,the time required for relative movement between the negative 528 andhalf-tone screen for a distance of millimeter equal to thewidth ofmillimeter of a. transparent dot of the half-tone screen.

The data given above are to be taken only as an example. Satisfactoryresults are obtained if the instantaneous exposures made automaticallyby the shutter at moments, when the half-tone screen is moved into aposition wherein its transparent dots pass over the loci of theprospective dots on the negative, take about 0 to /20 0f the timerequired for a movement of the half-tone screen through a distance equalto the width of a transparent dot of its pattern of dots. Furthermore,of course, a different type of a controlling mechanism could be used toobtain said features.

We have described preferred embodiments of our invention, but it is cle1' that numerous changes and omissions may be made Without departingfrom the spirit or our invention.

What we claim is:

1. In a photographic apparatus for the-production of dot-composednegatives from a positive, a stationary holder for a, negative in saidapparatus, a negative disposed in said holder, a mask adjacent saidnegative and having a Window, and a dot-composed half-tone screenmounted in said window and adjacent said negative and being smaller thannegative and including a pattern of alternating transparent and opaquedots, each two adjoining like dots bein spaced from each other for acertain distance in a predetermined direction, said screen beingmovable, with said mask, along said negative in a direction at a fixedangle to said predetermined direction, in combination with, means formoving said screen from one position to another along said negativecomprising guiding means and a series of registry means intermediatesaid movable screen and said stationary holder, said registry meansarranged to be spaced from each other for a distance constituting amultiple of said certain distance for preserving substantially exactdot-pattern continuity on said negative throughout the screenreproductions, and comprising a latch secured with relation to saidscreen and movable therewith, and a series of alt utrlent means spacedfrom each other for said last named distance and associated withrelation to said stationary holder and operable to bemoved into the pathof said latch engaging the same and to be moved out of said path fordisengagement from said latch and for subsequent movement of saidscreen, and electrically controlled means for impelling said abutmentmeans at leastv during one of said movements.

2. In aphotographic apparatus for the production of dot-composednegatives from a positive, a stationary holder for a negative in saidapparatus, a mask adjacent said negative and being movable along thesame and having an opening, and a dot-composed half-tone screen mountedto said mask at s -d openin and movable therewith and disposed adjacentsaid negative and being smaller than said negative and including aipattern of alternating transparent and opaque dots, each two."adjoining like dots being spaced from each other for a certain distancein a predetermined direction, in combination with, means for moving saidscreen and mask, and registry means for holding said screen in selectedpositions opposite said negative and comprising, a latch carried atleast with relation by said screen and movable therewith, a series ofspaced abutment means movable in and out of the path of said latch andhaving a surface for engagement with said latch and disengagementtherefrom to stop said screen at selected positions in its move underthe impulse of said driving means and. to release it for subsequentresumed move, respectively, each said surface spaced from an adjoiningsurface for a dis tance, adjusting means associated with each abutmentsurface for varying said distance to a (predetermined multiple of saidfirst named certain distance for preserving substantially exact dotpattern continuity on said negative, and electrically controlled meansoperable to move said abutment means out of said path for latch release.

3. In a photographic apparatus of the class described, in combination, adot-composed screen movable in front of a stationary negative, saidscreen arranged to produce a dot-continuous image in step-by-steprepeated exposures when moved for at least a single accuratelypredetermined distance, and means for moving said screen along saidnegative for a multiple of said distance comprising driving means formovement of said screen in one direction, registry means for saidnegative and screen including a latch associated with said screen, aseries of latch engaging members spaced substantially for said lastnamed distance and independently of the movement of said screen movablein and out of the path of said latch, and adjusting means for each ofsaid engaging members to vary the posi- 10 tion of effective engagementbetween said latch and a member said adjusting means including a screwand a threaded holder surrounding said screw and said screw beingrotatable for axial movement within said holder.

4. In a photographic apparatus of the class described, in combination, adot-composed screen including adjoining light and opaque spots andmovable in front of a stationary negative, said screen arranged toproduce a dot-continuous image in step-by-step repeated exposures whenmoved for at least a single accurately predetermined distance, and meansfor moving said screen along said negative for a multiple of thecombined width of a light and opaque spot comprising driving means formovement of said screen in one direction, registry means for saidnegative and screen including a latch associated with said screen, aseries of latch engaging members spaced substantially for said lastnamed distance and independently of the movement of said screen movablein and out of the path of said latch, adjusting means for each of saidengaging members to vary the position of effective engagement betweensaid latch and a member, and a solenoid interconnected to an electriccircuit and operable to efiectuate at least one of the movements of eachof said members.

LUDWIG MIES VAN DER ROI-IE. WALTER PETERHANS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,226,838 Wolber May 22, 19172,356,363 Thompson Aug. 22, 1944

